Source : Webster's Revised Unabridged Dictionary (1913)

Somniloquy \Som*nil"o*quy\, n.
   A talking in sleep; the talking of one in a state of
   somnipathy. [R.] --Coleridge.

Source : WordNet®

somniloquy
     n : uttering speech while asleep [syn: {sleep talking}, {somniloquism}]